Simply put, you require explosion-proof cable glands to ensure the protection of your electrical equipment and enclosures in a hazardous environment. However, knowing you need an explosion-proof cable gland and choosing the correct one is a different matter. After all, there are various factors, such as the type of cable, size, and ingress protection, to consider.

The most commonly used explosion-proof cable glands include single-compression and double-compression cable glands. But many business owners already have a tough time choosing between these two types of cable glands. That is fair, as you require knowledge of the equipment to make an informed choice. So let us help you make the best decision by sharing more details about these two types of cable glands.

Learn More: Explosion-Proof Cable Gland Selection Guide: Types And Applications

What is a single-compression explosion-proof cable gland?

Single-compression explosion-proof cable glands are often utilised for light-armoured cables in normal climatic conditions (both indoors and outdoors), providing electrical continuity between the gland entry component and the unarmoured cable. They also offer a seal on the outer sheath of the cable, ensuring no damage happens to the cable sheathing.

Crucial components of single-compression explosion-proof cable glands include:

• Flat washer – Distributes the fastener load over a much broader region and offers a flawless bearing surface.
• Lock nut – Ensures a nut stays in place and does not become loose.
• Rubber washer – Helps lower noise levels and avoid vibration distribution from one region to another.
• Neoprene rubber seal – Resists oxidation, ozone, sunlight, and petroleum derivatives.

What is a double-compression explosion-proof cable gland?

Double-compression explosion-proof cable glands offer compression at both the cable armour and inner sheath. This provides additional sealing and support to bulky armoured cables that enter and exit the panel. Hence, the likelihood of vapour or moisture entry is reduced. As a result, they are weatherproof and suitable for rougher climates. 

Such cable glands are often employed where large armoured wires are coming into or getting out of the board. Like single-compression explosion-proof cable glands, they can be used in corrosive settings when shielded by PVC shrouds.

Crucial components of double-compression explosion-proof cable glands include:

• Compression seal fitting – Designed to close elements, such as fibre optic cable, tube, pipe, conductor, wire, and probe, when they pass through an environmental or pressure boundary.
• Washer – A sealing washer located at the equipment-gland entry interface that provides protection. Its function depends on several factors, such as the ingress protection rating, the entry holes, and the equipment’s code of protection.
• Armour clamping ring and armour clamping cone – Made to tighten the metal-to-metal surface, thus offering a level of inspectability and reliability.

What are the differences between single-compression and double-compression explosion-proof cable glands?

In summary, single-compression explosion-proof cable glands are typically used for light-armoured cables, as they only offer grip or compression in one place, namely the cable armour. Therefore, it does not provide complete protection from moisture and corrosive vapour.

Conversely, double-compression explosion-proof cable glands offer protection at both the cable armour and inner sheath. With the double sealing, they help safeguard the cable from moisture, rendering it weatherproof. As a result, they are typically used to support heavy armoured cables. 

One last thing to note is that double-compression glands also comprise a cone and cone ring, which are absent in single-compression glands.

So as you can see, the usage of single and double-compression explosion-proof cable glands is largely dependent on the area in which they are utilised. Now that you have a better understanding of the merits of both types of explosion-proof cable glands, you can ensure you make the correct decision to ensure the overall integrity of your enclosure.

At Supermec, we offer a broad selection of explosion-proof cable glands, including armoured cable glands, to suit various hazardous work environments. Do not hesitate to contact us today if you need help selecting the ideal explosion-proof cable glands for your project.